Preparation of long-chain fatty acids



Patented Dec. 23,

PREPARATION OF LONG-CHAIN FATTY ACIDS Donald D.

Cofl'man, Wilmington, 1301.,

amino:

E. I. du' Pont de Nemourl dz Company, Wilmington, Del., a corporation ofDelaware No Drawing. Application March 17, 1945, Serial No. 583,396

1 12 Claims.

This invention relates to olefin reactions and particularly to a processfor reacting oleflns such as ethylene with organic carboxylic acids inthe presence of certain specific catalysts to be hereinafter disclosed.a

The type of reaction with which this invention is concerned isessentially a polymerization of the olefin in the presence of areactant, one molecule of which supplies both end groups for the longchain or modified polymeric molecule. For convenience, such a reactionmay be referred to as telomerization and the modified polymeric productsas telomers." In the copending application of W. E. Hanford and J. R.Roland, S. N. 471,028 filed January 1, 1943, it is disclosed thatethylene undergoes a telomerization" reaction with various saturatedorganic oxygen-containing materials in the presence oi! certaincatalysts which are considered to be effective as sources of freeradicals, namely, peroxides, persulfates, oxygen, perborates,percarbonates, hydrazines, tetraethyl lead, hexachloroethane and thelike. This kind of reaction is, of course, entirely unlike the ordinaryesterification of carboxylic acids by reaction with olefins, whichoccurs in the presence of strongly acidic or metal halide types ofcatalyst.

An object of this invention is toprovide an improved process forreacting ethylene with organic carboxylic acids. Another object is toprovide novel catalysts for the introduction of a polyethylene chaininto .organic carboxylic acids having at least one'hydrogen atomattached to an alpha carbon atom.

These and other objects are accomplished in accordance with thisinvention by heating ethylene with an organic carboxylic acid free ofolefinic and acetylenic unsaturation, and having at least onealpha-hydrogen atom, in the presence of a catalyst having a kN-group, asfor example, derived from an oxo compound (ketaldone) and preferably ofthe class consisting of azines,oximes, hydrazones, semicarbazones, andSchiff's bases, as hereinafter; more fully described. When ethylene isemployed as the sole olefinic reactant, the reaction which occurs inaccordance with the invention may be written as follows:

in which R1 and R: represent hydrogen, monovalent hydrocarbon groupsfree dfoleflnic and acetylenic unsaturation, and carboxyl-substitutedmonovalent hydrocarbon groups free of oleflnic and acetylenicunsaturation, and n is an integer, preferably having an average value offrom 6 to or more.

It is well known that when a carbonyl compound of the class consistingotaldehydes and ketones is caused to react with an amino compound of theclass consisting of hydroxylamines, hydrazines, semicarbazide, aniline(or other amines) and the like, or salts thereof, a derivative is formedin which the carbonyl group is replaced by the group, C=N-. Derivativesthus obtained constitute a olassot substances consisting of azines,oximes, hydrazones, semicarbazones and Schii'i's bases. These substancesare useful as catalysts in accordance with this invention. Schifl'sbases are condensation products of aromatic amines and aldehydes, andare structuraily analogous to aliphatic or aromatic derivativesoi-ketones or tives containing the C=N-group. The expression, Schifisbases, as used hereinafter, includes these analogous compounds.

The acids used for reaction with ethylene in this invention may be anyof the organic carboxylic acids which contain at least onealpha-hydrogen atom, which are free of olefinic and acetylenicunsaturation, and which preferably contain only carbon, hydrogen andoxyge More specifically, the acids useful in the practice of thisinvention include acetic, propionic, butyric, isobutyric, valeric, andhigher alkanoic acids containing at least one alpha-hydrogen atom suchas octanoic,decanoic,lauric and myristic and even higher acids.Branched-chain carboxylic acids. though .-less 'readily available, areof similar utility in this invention it they conform to the definitiongiven above. As such may be mentioned butane-2-carboxylic acid andpentane- S-carboxylic acid. Dimay also be used in carrying out thereaction of this invention it they also conform to the limitations setforth above. Suitable examples of such acids are succinic, glutaric,.adipic,

sebacic, and tricarballylic acids. In view of the greater ease ofavailability, it is generally preferred to practice this invention withthe lower molecular weight acids described, particularly with thosewhich contain less than '7 carbon atoms.

The reaction of ethylene and organic carboxylic acids according to thisinvention is sensitive to impurities or inhibitors, and it is thereforeespecially desirable that carefully purified acids be employed.

The ratios of ethylene to carboxylic acid in the initial reactionmixture may be varied widely.

aldehydes, said derlvaand poly-basic acids The preferred ratios inbatchwise operation are from about 1:8 to about 1:1.12 by weight,although still wider ratios of reactants, including the range from about1:30 to about 120.1, are operable. In a continuous process virtually anyratio of reactants may be employed. Control of the ratio of reactants isimportant since it affects the average molecular weight of the prod uct.While minor amounts of acids containing only one combined ethylene unitper molecule of the initial carboxylic acid are sometimes present in theproducts, in most instances the product is made up of acids containing alarger number of combined ethylene units.

The carboxylic acid reactant is preferably used in the absence ofsolvents or diluents. However, a diluent or solvent may be used, inwhich case his preferable to employ materials which do not themselvesreact with ethylene. For this purpose materials which are free ofsecondary and tertiary hydrogen atoms are preferred, such as tert.-butylmethyl ether, methyl pivalate, benzene, and chlorobenzene.Highly-branched and sterlcally-hindered compounds, even if they containsecondary or tertiary hydrogens, may also be used. Isooctane,pentamethylethane, etc. are such compounds.

This reaction can be applier to any polmerizable mono-olefinichydrocarbon preferably one containing less than five carbon atoms.Ethylene is the preferred olefin for use in the practice of thisinvention and should be the major component of olefinic gas used in thepractice thereof. The ethylene may contain small quantities of ethane,propane, nitrogen, hydrogen, carbon dioxide or oxygen. Oxygen in highconcentrations, for example, in excess of 1000 parts per million isgenerally deleterious to the reaction. Ethylene containing smalleramounts of oxygen, however, e. g. less than 100 P. P. M. (generally lessthan 50 P. P. M. and the preferably less than P. P. M.), is employedsince these concentrations have only minor effects on the yields andmolecular weights of the products produced. Commercial grades ofethylene frequently contain various impurities, and it is generallydesirable to purify the ethylene to attain low concentrations of allcontaminants, particularly oxygen and acetylene. Ethylene isconveniently purified by distillation, by catalytic removal ofcontaminants, or by scrubbing. I

As catalysts for inducing the reaction of this invention, any compoundmay be used which contains the group C=N-- and which is derived from aketaldone, i. e., a ketone or an aldehyde. Specific catalysts useful inthe practice of this invention include azines (containing the groupC'=NN=C such as benzalazine, heptaldazine and diphenylketazine; oximes(containing the group C=NOH) such as d-camphor oxime, acetone oximealpha-benzil dioxime, butyraldehyde oxime, alpha-benzoin oxime,dimethylglyoxime; hydrazones (containing the group C=NN-) such asbenzaldehyde phenylhydrazone, phenylhydrazones of cyclohexanone,cyclopentanone, acetophenone, menthone, camphor, and benzophenone;semicarbazones (containing the group C=N-NHCONHz) such as semicarbazonesof acetone, methyl ethyl ketone, diethyl ketone, biacetyl,eyclopentanone, cyclohexanone, acetophenone, propiophenone, camphor, andbenzophenone; Schiifs bases (containing the group C=N) such asbenzalaniline, benzalp-toluidine, benzal-o-toluidine, benzaldehydederivatives of methylamine, ethylamine, and heptylamine, acetaldehydeanil, acetone anil, isobutyraldehyde anil, heptaldehyde anil, etc. Thesecatalysts are generally used in amounts from about 0.001% to 0.5% byweight based on the total reactants. While it is generally notnecessary, for attaining extremely high rates of reaction or for otherspecial purposes, even higher amounts of catalysts may be used; forexample, amounts ranging up to as high as 1% or even 5% as an upperlimit. For their best utility in the practice of this invention, theforegoing catalysts should be highly purified. For example, some of thephenylhydrazones and some of the Schifis bases are relatively unstableand decompose on exposure to moisture or air. When the catalysts showsuch sensitivity they should be freshly prepared immediately before use.Some, such as benzalaniline, can be satisfactorily stored in a vacuum orunder a nitrogen atmosphere for a limited period of time.

In the practice of this invention, temperatures of about 50 to 400 C.are generally used, good results being obtained at about to 300 C. Incontinuous reactors, the preferred temperatures are from 150 to 400 C.depending upon the pressure, the activity of the catalyst, and also uponthe contact time.

Superatmospheric pressure is used in carrying out the process of thisinvention. Pressure and temperature are inversely interdependentvariables; that is, within the limits given, high reaction temperaturesgenerally permit the use of lower reaction pressures whereas lowreaction temperatures generally require relatively high pressures for acomparable rate of reaction. In order to obtain a high yield, and a highspace time yield, the process is generally operated at a pressure of 100atmospheres to 2000 atmospheres, or even higher. Pressures in the rangeof 500 to 1500 atmospheres are readily obtained, and are quitesatisfactory for most purposes. From the foregoing discussion, in thelight of the specific examples, one skilled in the art can readilyascertain optimum or near optimum conditions of temperature and pressureto apply to a chosen system. Other factors being equal, an increase intemperature makes for a decrease in the average molecular weight of theacid product while an increase in ethylene pressure makes for anincrease in the average molecular weight.

The equipment used in the practice of this invention may be fabricatedof, or lined with, suitable inert materials, such as stainless steel,silver, lead, tin, or glass.

In the following examples, employed is a high pressure shaker tube of400 cc. capacity. All parts are given in weight in c.- g. s. unitsunless otherwise stated.

Example 1.A silver-lined high-pressure vessel is charged with 200 partsof isobutyric acid and 0.2 part of benzalazine. The vessel is thenclosed, placed in a shaker machine, pressured with ethylene and heatingand agitation are started. During a reaction time of 14.4 hoursthroughout which the temperature is maintained at 220 to 226 C. and thepressure at 850 to 950 atmospheres there is a total observed pressuredrop of 665 atmospheres. The vessel is then cooled, bled of excess etylene, opened and the reaction mixture discharged. Distillation of thisreaction mixture gives parts of unreacted isobutyric acid 8.7 parts ofan acid mixture boiling at 113 to 114 C. at 16 mm. and having an acidnumber of 349.0, 10.5 parts of an acid mixture boiling at the reactionvessel [36 to 181 C. at 6 mm. pressure and having an acid number or252.2, 12 parts of an acid mixture boiling at 181 to 236 C. at 3 mm. andhaving an acid mixture of 182.0, 10.5 parts of an acid mixture boilingat 218 to 290 C. at 1.25 mm. and having an acid number of 58. The acidsof all of these fractions are saturated, free of neutral contaminantsand are readily soluble in organic solvents and in aqueous bases.Aqueous solutions of the alkaline salts foam strongly, wet sulfur and ingeneral show good surface active properties.

Example 2.-A silver-lined, pressure-resistant vessel is charged with 200parts -of isobutyric acid and 0.2 part of diphenyl-ketazine. The vesselis then closed, pressured with ethylene and run as described above.During a reaction time of 15.25 hours throughout V which the temperaturewas maintained at 224 to 253 C. and the pressure at 745 to 1000atmospheres, there is a total observed pressure drop of 1545atmospheres. The reaction mixture from this experiment yields 145 partsof an acid mixture which has an acid number of 168.5. average molecularweight of 332 and to an acid This analysis corresponds to an Example 6.--A series of experiments. tabulated below, shows the eil'ectof-temperature on the reaction. Two hundred parts of isobutyric acid and0.2 part of benzalazine are heated in a silverlined reaction vesselunder ethylene pressure of from 850 to 950 atmospheres at thetemperature shown in the table. The table further gives analytical dataon the acid mixtures produced from this system.

Run Temp. Yield Avg. No. OS

No. C. Parts Acld in Acid e 275 114 202. 2 27s 17. e

Example 7 .-The experiments listed below were designed to illustrate theinfluence of reactant ratio on mixed acid products. The amounts orisobutyric acid shown in the table areheated with 0.2 part benzalazineat 250 C. under 850 to 950 atmospheres ethylene pressure. The table alsogives analytical data on the acid mixtures obtained under these variousconditions.

Run lsobutlyric Ethylene, E Acid Yield, Acid Mol. Avg. No. C! No. Acid,arts Parts atio Parts No. Wt. in Add 1 These weights of ethylene may bein error by as much as about 6%.

mixture containing an average 01 21.4 carbon atoms.

Example 3.-The experiment of Example 2 is repeated except for thesubstitution of 0.2 part of d-camphoroxime for, the diphenyl-ketazinecatalyst. This reaction mixture yields a mixed acid product whose acidnumber of 196.7 corresponds to an average molecular weight of 285 and toan acid containing an average of 18 carbon atoms.

Example 4.--The experiment of Example 1 is repeated except for thesubstitution of 200 parts of propionic acid for the isobutyric acid ofthat example. During a reaction time of 14.5 hours throughout which thetemperature is maintained at 248 to 252 C. and the pressure at 850 to1050 atmospheres there is a total observed pressure drop of 885atmospheres. This reaction mixture yields 60 parts of a soft pasty acidmix-'- ture which has an acid number of 135.1. Thisv analysiscorresponds to an average molecular weight of 423 and to an acid mixturecontaining an average of 28 carbon atoms.

Example 5. -'Ihe experiments tabulated below illustrate the effect ofpressure on the reaction of this invention. These runs are carried outby heating 200 parts of isobutyric acid and 0.2 part of benzalazine in asilver-lined reaction vessel at 250 C. and under ethylene pressure inthe range given in the table. The table further shows analytical data onthe products obtained by reacting these systems at various ethylenepressures.

action conditions.

Example 8.-Silver-lined pressure-resistant vessels are charged with 200arts isobutyric acid and 0.2 part of the catalysts listed in thefollowing table. During the reaction, the temperature was maintainedat250 C. and the ethylene pressure at 850 to 950 atmospheres. The tablesummarizes the yield and analytical data.

Y id ?Z A id M 1' Y'C 10 S 011 I 0 0 0 81- Catalyst parts come)? No. Wt.bonin acid) acid Acetone semicarbazone. 45 0.5 185.8 802 10.8Benzaldehyde phenylhydrozone 79.4 10.6 181.0 300 19.8 Benzalanlline 7710.5 174.4 321 20.6

- The products obtained in accordance with the foregoing examples aremixtures whose compo-- nents are acids having the structure H(CH2CH2)11CR1R2COOH carbon groups free of oleflnic and acetylenic unsaturation,and where n 6 to 50 or more.

While batchwise operation has been described in the examples, theprocess of this invention may also be operated continuously. Aconvenient form of apparatus for use in the continuous process is a longtubular reactor, a portion of which is heated to the reactiontemperature. The reactants, including catalyst, separately or mixed inany desired proportion, are pumped through the reactor while the productis continuously removed. In such a. reactor the reactants may bepreheated or not before being submitted to re- If desired, the catalystmay has average values of many similar products from more reactions tolong-chain acid be injected at several points throughout the reactionzone. In this manner. a low and relatively constant catalystconcentration may be used, whereby the reaction velocity is readilyamenable to control. Under these conditions the heat of reaction isrelatively small in any portion of the reaction zone and is thereforeeasily removed.

It is generally preferable to maintain all the reactants in intimatecontact, which may be accomplished by any method of mixing, such as bycontinuous stirring, turbulent flow, atomization, etc., or by efllcientbubbling of the gaseous phase through the liquid phase of the reactionsystem.

The products of this invention are widely useful. These acid mixtures,in the form of their sodium or other alkali metal salts, show detergent,emulsifying and wetting properties. The heterogeneity of the products,which is only in respect to molecular weight, makes them superior tomany similar materials prepared by other means. For example, waterrepellents prepared therefrom are useful in the treatment of fabrics,and permit the treated fabric to retain a fine soft hand whereas manysimilar products confer a hard, boardy character. Moreover, theconversion of these acids to plasticizers and special lubricants, forexample by esteriflcation with short-chain alcohols, gives productswhich remain liquid at very low temperature while conventional sourcesfreeze at relatively high temperatures.

The products of this invention can be converted to useful waxes or waxadjuvants, for example by esterification with a long-chain alcohol orglycol, or by preparation of salts such as calcium and other alkalineearth salts as well as aluminum and zinc salts. Such compounds show awide range of compatibility with other waxes and wax solvents. Thealkaline earth and heavy metal salts may further be used asgrease-bodying agents, corrosion preventive ingredients and ascomponents of water-repellent and waterproofing compositions. The alkalimetal and ammonium salts of these acids are readily soluble in water andsuch solutions find use in detergent, emulsification, dispersion,wetting, textile dyeing and finishing applications. Many of such soapsare also easily soluble or dis-- persible in dry cleaning fluids such asnaphtha and polychloro compounds and these solutions or dispersions areof value as ying cleaning agents. The synthetic acids obtained by theprocess of this invention find use per set in the form of salts ascompounding ingredients and milling aids in the processing of naturaland synthetic rubbers. These also find use as antitack agents in thecalendering of plastics. A particularly valuable product, of use asawater repellent, can be prepared from these acid mixtures byconversion, via the amide, to N-hydroxvmethylamides. Still other typesof water repellents may be made by further reaction of theN-hydroxymethylamide with a tertiary amine salt to give a high grade,permanent water-repellent finish. The long-chain acid mixtures of thisinvention may also be transformed by known chlorides, anhydrides,alcohols, sulfates, chlorides, mercaptans, nitriles and amines. The usesfor which such secondary products can be manufactured are generally wellknown to the art. For example, the acid chlorides and anhydrides aredirectly useful as water-repellent finishes for paper and textiles, thealcohols as wax components and as 8 raw materials for sulfation to hardwater detergents, the mercaptans as modifiers for synthetic rubberpreparation and vinyl polymerizations in general, the mines as rawmaterials for cationic surface active agents.

I claim:

1. A process for the preparation of long-chain fatty acids whichcomprises reacting ethylene with a carboxyllc acid of the formulaHRrRaCOOOH, R1 and R: representing hydrogen, monovalent hydrocarbongroups free of oleflnic and acetylenic unsaturation, andcarboxyl-substituted monovalent hydrocarbon groups free of olefinic andacetylenic unsaturation, at a temperature within the range of 50 to 400C. under superatmospheric pressure in the presence of a catalyst of theclass consisting of azines. oximes, hydrazones, semicarbazones, andSchiif's bases, whereby a mixture of long-chain fatty acids of theformula H(CH2CH:);R1R2CCOOH, n being an integer, is obtained.

2. A process for the preparation of longchain fatty acids whichcomprises reacting ethylene with a. carboxylic acid of the formulaHRiRaCCOOH, R1 and R: representing hydrogen, monovalent hydrocarbongroups free of oleflnic and acetylenic unsaturation, andcarboxyl-substituted monovalent hydrocarbon groups free of oleflnic andacetylenic unsaturation. at a. temperature within the range of 50 to 400C. under a pressure of to 2,000 atmospheres in the presence of acatalyst containing a C=N- group, said catalyst being of the classconsisting of azines, oximes, hydrazones, semicarb'azones, and Schiff'sbases, whereby a mixture of longchain fatty acids of the formulaH(CH2CH2) n-RIR2CCOOH n being an integer, is obtained.

3. A process for the preparation of longchain fatty acids whichcomprises reacting 1.0 part by weight of ethylene with 0.1 to 30 partsby weight of a carboxylic acid of the formula HR1R2CCOOH, R1 and R2representing hydrogen, monovalent hydrocarbon groups free of olefinicand acetylenic unsaturation, and carboxyl-substituted monovalenthydrocarbon groups free of olefinic and acetylenic unsaturation, at atemperature within the range of 50 to 400 C. under a pressure of 100 to2000 atmospheres in the presence of a catalyst containing the C=N group,said catalyst being of the class consisting of ardnes, oximes,hydrazones, semicarbazones, and Schiifs bases, whereby a mixture oflongchain fatty acids of the formula H(CH2CH2) nR1R2CCOOH n being aninteger, is obtained.

4. A process for the preparation of long-chain fatty acids whichcomprises reacting. 1.0 part by weight of ethylene with 0.1 to 30 partsby weight of a carboxylic acid of the formula HR1R2CCOOH, R1 and R2representing hydrogen, monovalent hydrocarbon groups free of oleflnicand acetylenic unsaturation, and car-boxylsubstituted monovalenthydrocarbon groups free of olefinic and acetylenic unsaturation, saidcarboxylic acid having less than 7 carbon atoms per molecule, at atemperature within the range of 50 to 400 C. under a pressure of 100 to2000 atmospheres in the presence of a catalyst containing the (hN-group, said catalyst being of the class consisting of azines, oximes,hydrazones, semiacetylenic unsaturation,

carbazones. and Schiffs bases, whereby a mixture of long-chain fattyacids of the formula H(CH2CH2) nRiRzCcOOH n being an integer, isobtained.

5. A process for the preparation of long-chain fatty acids whichcomprises .reacting 1.0 part by weight of ethylene with 0.1 to 30 partsby weight of a carboxylic acid of the formula HRlR-ZCCOOH, R1 and R2representing hydrogen, monovalent hydrocarbon groups free of olefinicand acetylenic unsaturation, and carboxyl substituted monovalenthydrocarbon groups free of olefinic and said carboxylic acid having lessthan '7 carbon atoms per molecule, at a temperature within the range of150 to 300 0., under a pressure of 100 to 2000 atmospheres, in thepresence of a catalyst containing the. C=N group, said catalyst being ofthe class consisting of azines, oximes, hydrazones. semicarbazones, andSchiffs bases, whereby a mixture of long-chain fatty acids of theformula H(CH2CH2)1LR1R2CCOOH, n being an integer, is obtained.

6. A process for the preparation of long-chain fatty acids whichcomprises reacting 1.0 part by weight of ethylene with 0.1 to 30 partsby weight of a carboxylic acid of the formula HR1R2CCOOH, R1 and R2representing hydrogen, monovalent hydrocarbon groups free of oleflnicand acetylenic unsaturation, and carboxyl-substituted monovalenthydrocarbon groups free, of olefinic and acetylenic unsaturation, saidcarboxylic acid having less than '7 carbon atoms per molecule, at atemperature within the range of 150 to 300 C. under a pressure of 100 to2000 atmospheres, in the presence of an azine catalyst whereby a mixtureof long-chain fatty acids of the formula H(CH2CH2)1:R1R2CCOOH, n beingan integer, is obtained.

'7. A process for the preparation of long-chain fatty acids whichcomprises reacting 1.0 part by weight of ethylene with 0.1 to 30 partsby weight of a carboxylic acid of the formula HR1R2CCOOH, R1 and R2representing hydrogen, monovalent hydrocarbon groups free of olefinicand acetylenic unsaturation, and carboxyl-substituted monovalenthydrocarbon groups free of olefinic and acetylenic unsaturation, saidcarboxylic acid having less than '1 carbon atoms per molecule, at atemperature within the range of 150 to 300 C.,

under a pressure of 100 to 2000 atmospheres in the presence of an oximecatalyst, whereby a mixture of long-chain fatty acids of the formulaH(CH2CH2)1R1R2CCOOH, n being an integer, is obtained.

8. A process for the preparation of long-chain fatty acids whichcomprises reacting 1.0 part by whereby a mixture of long-chain fattyacids is weight of ethylene with 0.1 to 30 parts by weight I of acarboxylic acid of the formula HRiR2CCO0H, R1 and R2 representinghydrogen, monovalent hydrocarbon groups free of oleflnic and acetylenicunsaturation, and carboxyl-substituted monovalent hydrocarbon groupsfree of olefinic and acetylenic unsaturation, said carboxylic acidhaving less than 7 carbon atoms per molecule, at a temperature withinthe range of 150 to 300 C., under a pressure of to 2000 atmospheres inthe presence of a Schiffs base catalyst, whereby a mixture of long-chainfatty acids of the formula H CH2CH2MR1R2CCOOH n being an integer, isobtained.

l 9. A process for the preparation of long-chain fatty acids whichcomprises reacting 1.0 part by weight of ethylene with 0.1 to 30 partsby weight of isobutyric acid, at a temperature within the range of to300 0., under a pressure of 100 to 2000 atmospheres, in the presence ofa catalyst containing the C=N- group, said catalyst being of the classconsisting of azines, oximes, hydrazones, semicarbazones, and Schiff'sbases, whereby a mixture of long-chain fatty acids of the formulaH(CH2CH2) nC(CHs) 2000-H, n being an integer from 6 to 50; is produced.

10. A process for the preparation of long-chain range of 150 to 300 C.,under a pressure of 100- to 2000 atmospheres, in the presence ofcatalyst containing the C=N- group, said catalyst being of the classconsisting of azines, oximes, hydrazones, semicarbazones, and Schiffsbases, whereby a mixture of long-chain fatty acids of the formulaH(CH2CH2)1;CH(CH)3COOH, n being an integer fromfi to 50, is produced.

11. A process for the preparation of long-chain fatty acids whichcomprises reacting ethylene with an alkanoic carboxylic acid having atleast one alpha-hydrogen atom, at a temperature within the range of 50to 400 C. under superatmospheric pressure, in the presence of a catalystof the class consisting of azines, oximes, hydrazones, semicarbazones, vand Schiifs bases,

obtained.

12. A process for the preparation of long-chain fatty acids whichcomprises reacting ethylene with an alkanoic acid having at least onealphahydrogen atom at a temperature within the range of 50 to 400 C.under a pressure of 100 to 2000 atmospheres in the presence of acatalyst of the class consisting of azines, oximes, hydrazones,

semicarbazones, and Schiifs bases, whereby a.

mixture of long-chain fatty acids is obtained.

DONALD D. COFFMAN.

